Three-dimensional measuring system

Abstract

A system includes a polarization target having two or more surfaces, a polarization camera that captures an image of the polarization target and records polarization of light that formed the image, and a processor that determines an orientation of the polarization target based at least in part on the captured image and the determined polarization.

Description

FIELD OF THE INVENTION[0001]The subject matter disclosed herein relates to registration of three-dimensional (3D) data points obtained using triangulation scanners.BACKGROUND[0002]A triangulation scanner, also referred to as a 3D imager, uses a triangulation method to measure the 3D coordinates of points on an object. The triangulation scanner usually includes a projector that projects onto a surface of the object either a pattern of light in a line or a pattern of light covering an area. At least one camera and the projector are coupled together in a fixed relationship. For example, the projector and the one or more cameras may be attached to a common frame. The light emitted from the projector is reflected off the object surface and detected by the camera(s). Since the camera(s) and projector are arranged in a fixed relationship, the distance to the object may be determined using trigonometric principles. Compared to coordinate measurement devices that use tactile probes, triangul...

AI Technical Summary

Benefits of technology

[0009]In this or one or more other embodiments, the processor is further operable to determine a normal vector of a surface of the polarization target, the normal vector based at least in part on a determined polarization of light that formed an image of the surface. In this or one or more other embodiments, the processor is further operable to determine the normal vector of the surface of the polarization target based at least in part on a determined angle of polarization of the surface of the polarization target. In this or one or more other embodiments, the processor is further operable to determine a normal vector of a plurality of surfaces of the polarization target. In this or one or more other embodiments, the processor is further operable to determine the orientation of the polarization target based on an optimization program to minimize residual errors in the orientation.

Problems solved by technology

A challenge often faced in measuring relatively large objects with triangulation scanners is registering multiple sets of 3D points obtained with the triangulation scanner, the multiple sets being obtained by moving the scanner in relation to the object being measured.

A difficulty with this approach is that, to get good registration, it is usually necessary to use a large number of markers, with some of the markers located off a common plane.

In practice, an adequate arrangement of markers is often not achieved or achieved only with great effort.

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